TWI683842B - Method for producing a low-concentration gel by using a precursor gel cluster, and a gel obtained by the method - Google Patents

Abstract

An object of the present invention is to provide a low-concentration polymer content gel that can be produced in a short time and has controlled physical properties such as elastic modulus and swelling pressure.

The invention provides a method for manufacturing a polymer gel, which is characterized in that it is a method for manufacturing a polymer gel in which gel precursor groups are cross-linked with each other to form a three-dimensional network structure, and includes: a) making the criticality not reached The step of crosslinking the monomer unit or the polymer unit at a gelation concentration to form the gel precursor group, wherein the gel precursor group has G'in storage elastic modulus G'and loss elastic modulus G" The relationship of "G"; and b) The step of obtaining a gel with a three-dimensional network structure by cross-linking the aforementioned gel precursor groups with a cross-linking agent.

Description

Manufacturing method of low-concentration gel using gel precursor mass, and gel obtained by the manufacturing method

The invention relates to a novel polymer hydrogel.

In recent years, polymer gels with a network structure have excellent water-retaining ability and biocompatibility, so they have been paid attention to as embedding in vivo as materials for artificial tissues or regenerative scaffolds (Non-Patent Literature) 1). However, polymer gels have the following problems: in water, they will swell due to decomposition due to osmotic pressure or time-dependent changes in the concentration difference between the internal and external environments of the gel, so the surrounding tissues will cause compression damage.

Since the swelling pressure is proportional to the square of the polymer concentration constituting the gel, the effect due to swelling becomes particularly noticeable when the polymer concentration is high. Even if the degree of crosslinking is increased in order to reduce the swelling rate, the crosslinking will be cut due to changes over time, so reducing the polymer concentration becomes an essential solution. However, if the polymer concentration is reduced to the extent that no tissue damage due to swelling occurs, it is difficult to produce a gel in a short time using the previous method of manufacturing a polymer gel. In addition, when the polymer concentration is low and a gel is formed in a region near the gelation point, physical properties such as elastic modulus change drastically, so it is difficult to control the physical properties.

[Prior Technical Literature] [Non-patent literature]

[Non-Patent Document 1] Sakai et al., Macromolecules, 41, 5379-5384, 2008

[Non-Patent Document 2] Kurakazu et al., Macromolecules, 43, 3935-3940, 2010

[Non-Patent Document 2] Kamata et al., Science, 343, 873-875, 2014

Therefore, the object of the present invention is to develop a gel capable of avoiding the problem of tissue damage caused by swelling when buried in a living body and a method of manufacturing the gel, and its object is to provide an elastic modulus or swelling that can be produced in a short time Press the gel of low concentration and high polymer content with controlled physical properties.

The inventors of the present invention conducted intensive research in order to solve the above-mentioned problems, and found that by deliberately forming a state having a state immediately before gelation, in more detail, the storage elastic modulus G'is smaller than the loss elastic modulus G" The gel precursor group in the state, and used as a seed in the subsequent gelation reaction, can make the gel precursor group function as a polymer unit that is very gelable, and can be obtained in a short time A low-molecular-weight gel with controlled physical properties completes the present invention.

That is, the present invention provides in one aspect:

(1) A method for manufacturing a polymer gel, which is characterized in that it is a method for manufacturing a polymer gel in which gel precursor groups are cross-linked with each other to form a three-dimensional network structure, and includes: a) making the subcritical The step of crosslinking the monomer unit or the polymer unit at a gelation concentration to form the gel precursor group, wherein the gel precursor group has G'in storage elastic modulus G'and loss elastic modulus G" The relationship of <G"; and b) by using a cross-linking agent to make the above gel The step of cross-linking the precursor groups to obtain a gel with a three-dimensional network structure.

In addition, the preferred aspect of the manufacturing method of the present invention provides:

(2) The manufacturing method as described in (1) above, wherein the loss elastic modulus G" is in the range of 0.005 to 5 Pa at a frequency of 1 Hz;

(3) The manufacturing method as described in (1) or (2) above, wherein the gel precursor mass has a fragmented dimension of 1.5~2.5;

(4) The manufacturing method according to any one of (1) to (3) above, wherein the gel precursor mass has a diameter in the range of 10 to 1000 nm;

(5) The production method according to any one of (1) to (4) above, wherein the gel has a polymer content of 50 g/L or less;

(6) The production method according to any one of (1) to (5) above, wherein the monomer unit has a vinyl skeleton, or the polymer unit has a polyethylene glycol skeleton or a polyethylene skeleton;

(7) The production method according to any one of (1) to (6) above, wherein the gel precursor group includes a first polymer unit having one or more nucleophilic functional groups at the side chain or terminal, And a second polymer unit having more than one electrophilic functional group on the side chain or terminal;

(8) The production method as described in (7) above, wherein the nucleophilic functional group is selected from the group consisting of amine group, -SH, and -CO ₂ PhNO ₂ , and the electrophilic functional group is selected from N-hydroxy- Composed of succinimide (NHS) group, sulfosuccinimide group, maleimide group, phthalimide group, imidazolyl group, acryloyl group, and nitrophenyl group group;

(9) The manufacturing method according to the above (7) or (8), wherein the gel precursor group includes a first gel precursor group and a second gel precursor group, and the first gel precursor group 1 The content of the polymer unit is greater than the content of the second polymer unit, and the content of the second polymer unit of the second gel precursor group is greater than the content of the first polymer unit;

(10) The manufacturing method according to any one of (1) to (9) above, wherein the above step b) is performed with a reaction time within 1 hour; and

(11) The production method according to any one of the above (1) to (10), wherein the crosslinking agent in the above step b) is bis(sulfobutadiimide)glutarate (BS ₂ G ) Or DL-dithiothreitol (DTT), or a synthetic peptide with a thiol group at the end.

In another aspect, the present invention provides:

(12) A gel precursor group obtained by cross-linking monomer units or polymer units that have not reached the critical gelation concentration, and containing a solvent, storing the elastic modulus G'and the loss elastic modulus G" has the relationship of G'<G";

(13) The gel precursor group as described in (12) above, wherein the loss elastic modulus G" is in the range of 0.005 to 5 Pa at a frequency of 1 Hz;

(14) The gel precursor mass as described in (12) or (13) above, wherein the gel precursor mass has a fragmented dimension of 1.5-2.5;

(15) The gel precursor group according to any one of (12) to (14) above, wherein the gel precursor group has a diameter in the range of 10 to 1000 nm;

(16) The gel precursor group according to any one of (12) to (15) above, wherein the monomer unit has a vinyl skeleton, or the polymer unit has a polyethylene glycol skeleton or a polyethylene skeleton ;

(17) The gel precursor group according to any one of (12) to (16) above, which includes a first polymer unit having at least one nucleophilic functional group at the side chain or terminal, and at the side A second polymer unit having more than one electrophilic functional group at the chain or terminal; and

(18) The gel precursor group of (17) above, wherein the nucleophilic functional group is selected from the group consisting of an amine group, -SH, and -CO ₂ PhNO ₂ , and the electrophilic functional group is selected from N -Hydroxy-succinimide (NHS) group, sulfosuccinimide group, maleimide group, phthalimide group, imidazolyl group, acryloyl group, and nitrophenyl group The group formed.

In yet another aspect, the present invention provides:

(19) A polymer gel obtained by the production method as described in any one of (1) to (11) above;

(20) A polymer gel, characterized in that it is formed by cross-linking polymer units to form a three-dimensional network structure, and contains a solvent, has a polymer content of 50 g/L or less, and a frequency of 1 Hz It is the storage elastic modulus G'of 1~10000Pa and the broken dimension of 1.5~3.0;

(21) The polymer gel as described in (20) above, which has a loss elastic modulus G" of 1-100 Pa;

(22) The polymer gel according to (20) or (21) above, wherein the monomer unit has a vinyl skeleton, or the polymer unit has a polyethylene glycol skeleton or a polyethylene skeleton;

(23) The polymer gel according to any one of (20) to (22) above, wherein the polymer unit includes a first polymer unit having one or more nucleophilic functional groups at the side chain or terminal, And a second polymer unit having more than one electrophilic functional group on the side chain or terminal;

(24) The polymer gel of (23) above, wherein the nucleophilic functional group is selected from the group consisting of amine groups, -SH, and -CO ₂ PhNO ₂ , and the electrophilic functional group is selected from N- Hydroxy-succinimide (NHS) group, sulfosuccinimide group, maleimide group, phthalimide group, imidazolyl group, propenyl group, and nitrophenyl group Formed group

(25) The polymer gel according to any one of (20) to (24) above, which is the volume of the polymer gel in the range of 30 to 40°C in the aqueous solution relative to the gel The swelling degree of the volume is in the range of 90~500% volume change, and has a swelling pressure of 0.001~5kPa; and

(26) The polymer gel of (25) above, wherein the swelling degree is in the range of 100 to 200%, and the swelling pressure is 0.1 to 2 kPa.

According to the present invention, by deliberately using the gel precursor mass formed in the state immediately before gelation as a seed to gel it, it is possible to control the elastic modulus, swelling degree, etc. In a short time, a low concentration polymer content gel is produced in a short time. This can provide a gel that can avoid tissue damage caused by swelling when buried in a living body. The gel can be applied to closed or semi-closed cavities in living bodies such as artificial vocal cords.

FIG. 1 is a schematic diagram showing the outline of the manufacturing method of the present invention.

Fig. 2 is a graph showing changes in elastic modulus over time in a general gelation step.

FIG. 3 is a graph showing the time change of the elastic modulus in step a) of the manufacturing method of the present invention.

FIG. 4 is a graph showing the time change of the elastic modulus in step b) of the manufacturing method of the present invention.

FIG. 5 is a graph showing the gelation time for the case (△) and the comparative example (○) of the present invention using the gel precursor group 1 [TAPEG+TNPEG].

FIG. 6 is a graph showing the gelation time for the case (○) and the comparative example (□) of the present invention using the gel precursor group 2 [SHPEG+MAPEG].

7 is a graph showing the size distribution of gel precursor group 1 [TAPEG+TNPEG].

FIG. 8 is a graph showing the results of measuring the dynamic viscosity characteristics at the gelation critical point of gel precursor group 1 [TAPEG+TNPEG].

FIG. 9 is a graph showing the fragment dimension of gel precursor group 1 [TAPEG+TNPEG].

FIG. 10 is a graph showing the dependence of the polymer concentration of the elastic modulus in polymer gel 1 [TAPEG+TNPEG].

FIG. 11 is a graph showing the dependence of the polymer concentration on the elastic modulus in polymer gel 2 [SHPEG+MAPEG].

FIG. 12 is an image showing the time change of the swelling of the polymer gel 1 [TAPEG+TNPEG] in a semi-closed space.

FIG. 13 is a graph showing the results of measuring the time change of swelling pressure for hydrogel 2 [SHPEG+MAPEG].

Hereinafter, an embodiment of the present invention will be described. The scope of the present invention is not limited to these descriptions. In addition to the following examples, it can be implemented with appropriate changes within the scope not detracting from the gist of the present invention.

FIG. 1 is a schematic diagram showing the outline of the manufacturing method of the present invention. As the first step, as shown in FIG. 1 a ), the monomer unit or polymer unit that finally constitutes the polymer gel (hereinafter, this is referred to as “precursor unit”.) It reacts in a state to form a polymer group having a structure that has not yet formed a gel, that is, a sol state. And, as the second step, as shown in FIG. 1b), it is characterized by adding an appropriate cross-linking agent to further react the groups (gel precursor groups) to cross-link three-dimensionally with each other, thereby obtaining as the final The polymer gel of the product. Among them, the gel precursor group is not necessarily limited to a single composition of the same composition as described below, and multiple types of gel precursor groups with different compositions may also be used.

The present invention is based on the novel concept of using the gel precursor group as a so-called final gel precursor or intermediate. From this, it was found that even in the case of a low concentration of polymer content, the gel can be formed in a short time, and that the elastic modulus of the gel can be controlled even in the low elastic region, which is a difficult method for the prior art . Among them, the so-called "gel" usually refers to a dispersion system that loses fluidity at high viscosity.

(1) Gel precursor mass

As described above, the gel precursor group used in the present invention is a sol-like polymer group obtained by reacting the precursor unit under the condition before gelation, that is, the condition that the critical gelation concentration is not reached. . Among them, "critical gelation concentration" means the lowest concentration of precursor units necessary to achieve the gelation in a system in which a gel of a three-dimensional structure is constructed by crosslinking of specific precursor units. The lowest gelation concentration. In the present invention, the term critical gelation concentration includes, for example, in addition to the case where the system uses two or more precursor units, the overall concentration does not reach the gelation concentration. 1 case where the concentration of the precursor unit is low, that is, the ratio of each precursor unit is not Equivalent without gelling.

Although the gel precursor group has a structure in which the precursor units are bonded or cross-linked to each other, since they are formed under conditions that have not yet reached gelation, there are unreacted substituents in the precursor units . By making the substitution based on the formation of further cross-links in the reaction between the gel precursor groups, a final polymer gel with a three-dimensional network structure is obtained.

The storage elastic modulus G'of the gel precursor mass and the loss elastic modulus G" have a relationship of G'<G". As shown in Fig. 2, usually in the polymer before gelation, the value of the loss elastic modulus G" is larger than the storage elastic modulus G', and thereafter, with the gelation, the values of the physical properties are reversed. G'becomes larger. And the point where G'=G" is the so-called gelation point. Therefore, if the gel precursor group is G'<G", it means that it is in a sol state and has not yet reached the state of gelation. Preferably, it is G'<G"<100 G'at a frequency of 1 Hz.

The G" of the gel precursor mass is preferably in the range of 0.005 to 5 Pa at a frequency of 1 Hz, more preferably in the range of 0.01 to 1 Pa, and even more preferably in the range of 0.01 to 0.5 Pa. The elastic modulus can use flow The well-known measuring equipment such as a transformer is calculated by a well-known method such as dynamic viscoelasticity measurement.

In addition, the gel precursor mass in the present invention preferably has a fragmented dimension of 1.5 to 2.5. More preferably, it has a broken dimension of 1.5~2.0. Among them, the so-called fractal dimension is an index based on how close the cross-linked structure of the polymer unit is to the state of the three-dimensional structure, and the calculation method can refer to "W. Hess, TA Vilgis, and HH Winter, Macromolecules 21,2536 ( 1988)". Specifically, for example, it can be calculated using the dynamic scaling theory based on the change in dynamic viscoelastic properties under the gelation point.

The gel precursor mass in the present invention preferably has a diameter of 10 to 1000 nm, and more preferably has a diameter of 50 to 200 nm. In addition, it is preferable that the gel precursor groups having a diameter of about 100 nm exist in the distribution with the largest ratio.

The precursor units used to form the gel precursor group can be The monomer or polymer that forms a gel by a gelation reaction (crosslinking reaction, etc.) can be used as known in the technical field according to the final use or shape of the gel. In more detail, it is preferable that in the final gel obtained from the gel precursor group, polymer units capable of forming a network structure, particularly a three-dimensional network structure, by polymer crosslinking with each other.

Examples of the monomer unit used to form the gel precursor group include those having a vinyl skeleton. In addition, as the polymer unit for forming the gel precursor group, representatively include polymer species having a branched chain of a plurality of polyethylene glycol skeletons, particularly preferably a branch having four polyethylene glycol skeletons Chain polymer species. Gels containing the four-branched polyethylene glycol backbone are generally known as Tetra-PEG gels. They have an electrophilic functional group such as an active ester structure at the end and a nucleophilic functional group such as an amine group. An AB-type cross-coupling reaction between four branched polymers to build a network structure network. Regarding Tetra-PEG gel, according to previous research, it has been reported that the polymer network in the size region below 200nm has no unevenness and has an ideal uniform network structure (Matsunaga et al., Macromolecules, Vol. 42, No. 4, pp .1344-1351, 2009). In addition, Tetra-PEG gel can be easily produced on the spot using a simple two-component mixing of each polymer solution, and the gelation time can also be controlled by adjusting the pH or ionic strength during gel preparation. Moreover, since this gel system uses PEG as a main component, it is also excellent in biocompatibility.

However, if cross-linking is possible to form a network structure network, polymers other than the polyethylene glycol skeleton can also be used. For example, a polymer having a polyethylene skeleton such as methyl methacrylate can also be used.

It is not necessarily limited to these, but in order to form a network structure network in the final gel, it is preferable that the polymer unit forming the gel precursor group has more than one nucleophilic function at the side chain or at the end A method in which two kinds of polymers of a first polymer unit of a group and a second polymer unit having at least one electrophilic functional group on a side chain or terminal react and crosslink. Among them, the total of nucleophilic functional groups and electrophilic functional groups is preferably 5 or more. These functional groups are preferably present at the terminal. Also, the gel precursor group may be the first polymerization The content of the material unit may be greater than the content of the second polymer unit, or the content of the second polymer unit may be greater than the content of the first polymer unit. As described below, in a preferred aspect, two or more kinds of gel precursor groups having different compositions can be cross-linked to obtain a polymer gel.

Examples of the nucleophilic functional group present in the polymer unit include amine groups, -SH, or -CO ₂ PhNO ₂ (Ph represents o-, m-, or p-phenylene), and the like can be appropriately used by the industry. Nuclear functional group. The nucleophilic functional group is preferably a -SH group. The nucleophilic functional groups may be the same or different, but preferably the same. With the same functional group, the reactivity with the electrophilic functional group forming the crosslink bond becomes uniform, and it becomes easy to obtain a gel with a uniform three-dimensional structure.

As the electrophilic functional group present in the polymer unit, an active ester group can be used. Examples of such active ester groups include N-hydroxy-succinimide (NHS), sulfosuccinimide, maleimide, phthalimide, and imidazolyl. , Propylene acetyl or nitrophenyl, etc., the industry can use other well-known active ester groups. The electrophilic functional group is preferably a maleimide group. The electrophilic functional groups may be the same or different, but preferably the same. By having the same functional group, the reactivity with the nucleophilic functional group forming the crosslink bond becomes uniform, and it becomes easy to obtain a gel with a uniform three-dimensional structure.

As a polymer unit having a nucleophilic functional group at the terminal, preferred non-limiting specific examples include a branch having 4 polyethylene glycol skeletons and an amine group at the terminal represented by the following formula (I) Of compounds.

In formula (I), R ¹¹ to R ¹⁴ are the same or different, and C ₁ -C ₇ alkylene, C ₂ -C ₇ alkenyl, -NH-R ¹⁵ -, -CO-R ¹⁵ -, -R ¹⁶ -OR ¹⁷ -, -R ¹⁶ -NH-R ¹⁷ -, -R ¹⁶ -CO ₂ -R ¹⁷ -, -R ¹⁶ -CO ₂ -NH-R ¹⁷ -, -R ¹⁶ -CO-R ¹⁷ -, Or -R ¹⁶ -CO-NH-R ¹⁷ -, wherein R ¹⁵ represents C ₁ -C ₇ alkylene, R ¹⁶ represents C ₁ -C ₃ alkylene, R ¹⁷ represents C ₁ -C ₅ alkylene .

n ₁₁ ~ n ₁₄ may be the same or different. The closer the values of n ₁₁ to n _{14 are} , the more uniform the three-dimensional structure can be obtained and the higher the strength. Therefore, in order to obtain a high-strength gel, it is preferably the same. If the value of n ₁₁ ~ n ₁₄ is too high, the strength of the gel becomes weak. If the value of n ₁₁ ~ n ₁₄ is too low, it is not easy to form a gel due to the steric hindrance of the compound. Therefore, n ₁₁ to n ₁₄ may be an integer value of 25 to 250, preferably 35 to 180, more preferably 50 to 115, and particularly preferably 50 to 60. In addition, examples of the molecular weight include 5×10 ³ to 5×10 ⁴ Da, preferably 7.5×10 ³ to 3×10 ⁴ Da, and more preferably 1×10 ⁴ to 2×10 ⁴ Da.

In the above formula (I), R ¹¹ to R ¹⁴ are the connection sites connecting the functional group and the core part. R ¹¹ to R ¹⁴ may be the same or different, but in order to produce a high-strength gel with a uniform three-dimensional structure, it is preferably the same. R ¹¹ ~R ¹⁴ represent C ₁ -C ₇ alkylene, C ₂ -C ₇ alkenyl, -NH-R ¹⁵ -, -CO-R ¹⁵ -, -R ¹⁶ -OR ¹⁷ -, -R ^16- NH-R ¹⁷ -, -R ¹⁶ -CO ₂ -R ¹⁷ -, -R ¹⁶ -CO ₂ -NH-R ¹⁷ -, -R ¹⁶ -CO-R ¹⁷ -, or -R ¹⁶ -CO-NH-R ¹⁷ -. Among them, R ¹⁵ represents a C ₁ -C ₇ alkylene group. R ¹⁶ represents C ₁ -C ₃ alkylene. R ¹⁷ represents C ₁ -C ₅ alkylene.

Among them, the so-called "C ₁ -C ₇ alkylene" refers to an alkylene group which may have a branched carbon number of 1 or more and 7 or less, refers to a linear C ₁ -C ₇ alkylene or has 1 or Two or more branched C ₂ -C ₇ alkylene groups (including the branched carbon number of 2 or more and 7 or less). Examples of C ₁ -C ₇ alkylene are methylene, ethyl, propyl, and butyl. Examples of C ₁ -C ₇ alkylene extenders include -CH ₂ -, -(CH ₂ ) ₂ -, -(CH ₂ ) ₃ -, -CH(CH ₃ )-, -(CH ₂ ) ₃ -,- (CH(CH ₃ )) ₂ -, -(CH ₂ ) ₂ -CH(CH ₃ )-, -(CH ₂ ) ₃ -CH(CH ₃ )-, -(CH ₂ ) ₂ -CH(C ₂ H ₅ )-, -(CH ₂ ) ₆ -, -(CH ₂ ) ₂ -C(C ₂ H ₅ ) ₂ -, and -(CH ₂ ) ₃ C(CH ₃ ) ₂ CH ₂ -, etc.

The so-called "C ₂ -C ₇ alkenyl group" refers to an alkenyl group having 2 to 7 carbon atoms in the shape of a chain or branched chain having one or more than two double bonds in the chain. The divalent group of the double bond formed by removing 2 to 5 hydrogen atoms of adjacent carbon atoms in the alkylene group.

On the other hand, as a polymer unit having an electrophilic functional group at the end, it is Preferred non-limiting specific examples include, for example, compounds represented by the following formula (II) having a branched chain of four polyethylene glycol skeletons and an N-hydroxy-succinimide (NHS) group at the terminal.

In the above formula (II), n ₂₁ to n ₂₄ may be the same or different. The closer the value of n ₂₁ ~ n _24, the more the gel can obtain a uniform three-dimensional structure and become a high strength, so it is better, and therefore preferably the same. If the value of n ₂₁ ~ n ₂₄ is too high, the strength of the gel becomes weak. If the value of n ₂₁ ~ n ₂₄ is too low, it is not easy to form a gel due to the steric hindrance of the compound. Therefore, n ₂₁ to n ₂₄ may be an integer value of 5 to 300, preferably 20 to 250, more preferably 30 to 180, further preferably 45 to 115, and still more preferably 45 to 55. The molecular weight of the second four-branched compound of the present invention includes 5×10 ³ to 5×10 ⁴ Da, preferably 7.5×10 ³ to 3×10 ⁴ Da, and more preferably 1×10 ⁴ to 2× 10 ⁴ Da.

In the above formula (II), R ²¹ to R ²⁴ are the connection sites connecting the functional group and the core part. R ²¹ ~ R ²⁴ may be the same or different, but in order to produce a high-strength gel with a uniform three-dimensional structure, it is preferably the same. In formula (II), R ²¹ to R ²⁴ are the same or different, and represent C ₁ -C ₇ alkylene, C ₂ -C ₇ alkenyl, -NH-R ²⁵ -, -CO-R ²⁵ -,- R ²⁶ -OR ²⁷ -, -R ²⁶ -NH-R ²⁷ -, -R ²⁶ -CO ₂ -R ²⁷ -, -R ²⁶ -CO ₂ -NH-R ¹⁷ -, -R ²⁶ -CO-R ^27- , Or -R ²⁶ -CO-NH-R ²⁷ -. Among them, R ²⁵ represents a C ₁ -C ₇ alkylene group. R ²⁶ represents C ₁ -C ₃ alkylene. R ²⁷ represents C ₁ -C ₅ alkylene.

In this specification, the alkylene group and the alkenyl group may have one or more arbitrary substituents. Examples of the substituent include an alkoxy group, a halogen atom (which may be any of a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an amine group, a single or disubstituted amine group, Substitute silane group, acetyl group, or aryl group, etc., but not limited thereto. When the alkyl group has two or more substituents, they may be the same or different. The same applies to the alkyl portion of other substituents (such as alkoxy or aralkyl groups) containing an alkyl portion.

In addition, in this specification, when a certain functional group is defined as "may have a substituent", the type, substitution position, and number of substituents of the substituent are not particularly limited, but have 2 or more substituents In this case, they may be the same or different. Examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, a carboxyl group, a halogen atom, a sulfo group, an amine group, an alkoxycarbonyl group, and a pendant oxygen group, but are not limited thereto. There may be further substituents on these substituents.

In the case of the polymer unit of the above formula (I) and formula (II), a gel precursor group whose structure is connected by an amide bond can be obtained. Furthermore, as described below, in this case, in the gel finally obtained, each polymer unit is also a structure cross-linked by an amide bond.

(2) Gelation step

As a typical aspect of the gelation reaction step in the manufacturing method of the present invention, it includes: a) crosslinking monomer units or polymer units (precursor units) that have not reached the critical gelation concentration to form a gel The step of the precursor group (Figure 1a); b) The step of obtaining a gel with a three-dimensional network structure as the final target by cross-linking the aforementioned gel precursor groups with a cross-linking agent (Figure 1b) .

In step a), as described above, by adjusting the initial concentration of the precursor unit, the precursor unit is reacted under the condition that the critical gelation concentration is not reached to form a sol state that has not reached gelation, preferably It is a mass of polymer with a structure just before gelation. This group can be described as a precursor relative to the final gel, so in this application, this group is referred to as a "gel precursor group".

As a method for adjusting the initial concentration of the precursor unit to a condition that does not reach the critical gelation concentration, for example, when using a nucleophilic functional group or an electrophilic functional group as described above In the case of 2 types of polymer units, it can be used: the equivalent concentration is included but the gel concentration as a whole has not reached the low concentration condition; or by setting the concentration of 1 type of polymer unit to a low concentration, it is set to non- Equivalent conditions without gelation.

Generally, the critical gelation concentration (minimum gelation concentration) depends on the type of precursor unit used, but the concentration is well known in the technical field and can be easily grasped by an experimenter by experiment. Typical is 5~50g/L, and the lower limit is about 1/5 of the overlapping concentration. The overlapping concentration is the concentration of the polymer unit filled in the solution. For the calculation method, for example, refer to Polymer Physics (by M. Rubinstein, R. Colby). Specifically, for example, it can be obtained by measuring the viscosity of a dilute solution and using the Flory-Fox equation.

Step a) can typically be performed by mixing a solution containing 2 precursor units or applying a stimulus. Moreover, it can also be performed by radical polymerization of the monomer using a radical initiator. The concentration, addition speed, mixing speed, and mixing ratio of each solution are not particularly limited, and can be appropriately adjusted by the manufacturer. It can also be seen that, when three or more precursor units are used, a solution containing the corresponding precursor units can be prepared in the same manner and appropriately mixed. As the solvent of the solution containing the precursor unit, alcohols such as water and ethanol, DMSO (Dimethyl sulfoxide, dimethyl sulfoxide), etc. can be used. When the solution is an aqueous solution, an appropriate pH buffer such as phosphate buffer can be used.

As a method of mixing, for example, a two-liquid mixing syringe as disclosed in International Publication WO2007/083522 can be used. The temperature of the two liquids at the time of mixing is not particularly limited, as long as the precursor units are dissolved separately, and each liquid may be in a state of fluidity. For example, as the temperature of the solution at the time of mixing, the range of 1°C to 100°C may be mentioned. The temperature of the two liquids can also be different, but when the temperature is the same, the two liquids are easy to mix, so it is better.

Next, in step b), the gel precursor groups obtained in step a) are further reacted to crosslink them three-dimensionally, thereby obtaining a polymer gel as a final product. As described above, since the gel precursor group is formed in a state before the gelation point, the substituent used for crosslinking in each precursor unit remains in an unreacted state. By making the gel precursor The substituent in the mass reacts with the remaining substituents of other gel precursors to form a final gel.

Preferably, in this step b), a cross-linking agent for cross-linking the gel precursor groups may be added or a stimulus may be applied. As such a crosslinking agent, those having the same substituent as the crosslinking group in the polymer unit can be used, or the polymer unit itself can be used as a crosslinking agent and added additionally. For example, in step a), when two polymer units having a nucleophilic functional group or an electrophilic functional group are reacted in an unequivalent amount to obtain a gel precursor group, by adding The cross-linking agent of the functional group can cross-link the gel precursor groups. As such a crosslinking agent, bis(sulfosuccinimide) glutarate (BS ₂ G) or DL-dithiothreitol (DTT), or a synthesis having a thiol group at the terminal can be used Peptides, etc. In addition, as a stimulus for crosslinking, for example, a functional group (maleimide group, etc.) that causes photodimerization may be irradiated with ultraviolet light.

Preferably, in step b), the final gel can be obtained with a reaction time within 2 hours, preferably within 1 hour. Generally, when making a gel containing a polymer at a low concentration, a long reaction time is required (depending on the system, for example, about 8 hours when the polymer content is 10 g/L or less), compared to this, In the present invention, the gel can be produced in a very short time.

The conditions of the other reaction solutions in step b) are the same as in step a).

(3) Polymer gel

The polymer gel-based polymer obtained by the present invention has a low concentration, can be obtained with a short reaction time as described above, and can control the physical properties such as elastic modulus within a desired range. As shown in FIG. 2, the elastic modulus generally increases sharply near the gelation point, so it is difficult to obtain a low elastic modulus gel controlled to a specific value within a low elastic modulus range of 10 to 1000 Pa. In contrast, the gel of the present invention has a modulus of elasticity controlled in a low-elasticity region because the gel is produced through the aforementioned gel precursor group.

Therefore, the polymer gel of the present invention is characterized in that it is composed of polymer units Cross-linked to form a three-dimensional network structure, and has a low concentration of polymer content, a low area of elastic modulus, and a specific broken dimension.

The polymer content of the polymer gel of the present invention is 50 g/L or less, preferably 40 g/L or less, and more preferably 15 to 30 g/L.

The polymer gel of the present invention has a storage elastic modulus G'of 1~10000Pa, preferably 10~1000Pa. This range corresponds to the vitreous body (number 10Pa) or vocal cord (number 100Pa) in the living body. In addition, it is preferable that the polymer gel of the present invention has a loss elastic modulus G" of 1 to 100 Pa. These elastic modulus can be calculated by a known method using a known measuring machine.

Furthermore, the polymer gel of the present invention preferably has a broken dimension of 1.5 to 2.5. More preferably, it has a broken dimension of 1.5~2.0. The fragmented dimension is an index indicating how close the cross-linked structure in the gel is to the state of the three-dimensional structure. The calculation method is as described above and is well known in the technical field.

The polymer gel of the present invention is the swelling degree of the volume of the polymer gel in the range of 30-40°C in the aqueous solution in the range of 90-500% of the volume change with respect to the volume when the gel is made, and With swelling pressure of 0.001~5kPa. Preferably, the swelling degree is in the range of 100 to 200%, and the swelling pressure is 0.1 to 2 kPa. Lower swelling pressure means that the pressure applied to the outside is lower when the gel is placed in an enclosed space. That is, it means that even when the body absorbs water and swells over time, the tissue damage is low.

The polymer unit constituting the polymer gel of the present invention can be the same as the case of the gel precursor group described above. In a preferred aspect, the gel precursor group includes a first polymer unit having more than one nucleophilic functional group on the side chain or terminal, and has more than one electrophilic functional group on the side chain or terminal In the case of the second polymer unit, the gel precursor group can be used as the first gel precursor group of a composition in which the content of the first polymer unit is greater than the content of the second polymer unit, and as the second The two kinds of gel precursor groups of the second gel precursor group composed of the polymer unit whose content is more than the content of the first polymer unit can be the It is a polymer gel with a three-dimensional network structure formed by crosslinking two kinds of gel precursor groups with different compositions.

The polymer gel of the present invention can be processed into various shapes such as a film shape according to its application. Such processing can be applied to any method known in the technical field. For example, in the case of a thin film, the thin film can be obtained, for example, by coating on a flat substrate such as glass with fluidity before the gel is completely cured.

[Example]

Hereinafter, the present invention will be described in further detail by examples, but the present invention is not limited to these.

[Example 1]

Synthesis of polymer units

TAPEG (tetraamine-polyethylene glycol) and TNPEG (N-hydroxy-butane) are obtained by amination of THPEG (tetrahydroxy-polyethylene glycol) having a hydroxyl group at the terminal and iminoylation of succinimide, respectively. Diimino-polyethylene glycol (NHS-PEG)).

In addition, SHPEG (tetrathiol-polyethylene glycol) having a -SH group at the end and MAPEG (tetramaleimide-polyethylene glycol) having a maleimide group at the end are used by Japan Marketer of Oil Co., Ltd. The molecular weight is 10,000.

In the following experiment, the ¹ H NMR spectrum was analyzed using JNM-ECS400 (400 MHz) from JEOL. Deuterochloroform was used as the solvent, and tetramethylsilane was set as the internal standard. The molecular weight is determined using the linear cation mode of Bruflex Daltonics' mass spectrometer Ultraflex III.

1. Synthesis of THPEG:

Dissolve the initiator pentaerythritol (0.4572mmol, 62.3mg) in a mixed solvent of 50mL of DMSO/THF (v/v=3:2), use potassium naphthalene (0.4157mmol, 1.24mg) as the metallizing agent, add ethylene oxide Alkanes (200 mmol, 10.0 mL) were heated and stirred at 60° C. for about 2 days in the presence of Ar. After the reaction, let it reprecipitate in diethyl ether The precipitate is extracted by filtration. Furthermore, it was washed three times with diethyl ether, and the obtained white solid was dried under reduced pressure, thereby obtaining 20 k of THPEG.

2. Synthesis of TAPEG:

After THPEG (0.1935 mmol, 3.87 g, 1.0 equiv) was dissolved in benzene and lyophilized, it was dissolved in 62 mL of THF, and triethylamine (TEA) (0.1935 mmol, 3.87 g, 1.0 equiv) was added. In another round bottom flask, 31 mL of THF and mesyl chloride (MsCl) (0.1935 mmol, 3.87 g, 1.0 equiv) were added and placed in an ice bath. The THF solution of MsCl was added dropwise to the THF solution of THPEG and TEA over about 1 minute, stirred for 30 minutes in an ice bath, and then stirred at room temperature for 1.5 hours. After the reaction was completed, it was reprecipitated in diethyl ether, and the precipitate was extracted by filtration. Furthermore, it was washed three times with diethyl ether, the obtained white solid was transferred to a round bottom flask, 250 mL of 25% ammonia water was added, and stirred for 4 days. After the reaction was completed, the solvent was distilled off under reduced pressure with an evaporator, and the water was dialyzed against the external liquid two or three times, and lyophilized, thereby obtaining TAPEG as a white solid. The chemical formula of TAPEG produced is shown in formula (Ia). In formula (Ia), n ₁₁ to n ₁₄ are 50 to 60 when the molecular weight of TAPEG is about 10,000 (10 kDa), and 100 to 115 when the molecular weight is about 20,000 (20 kDa).

3. Synthesis of TNPEG:

THPEG (0.2395 mmol, 4.79 g, 1.0 equiv) was dissolved in THF, 0.7 mol/L glutaric acid/THF solution (4.790 mmol, 6.85 mL, 20 equiv) was added, and stirred for 6 hours in the presence of Ar. After the reaction was completed, it was added dropwise to 2-propanol and centrifuged three times using a centrifuge. The obtained white solid was transferred to a 300 mL round bottom flask, and the solvent was distilled off under reduced pressure by an evaporator. The residue was dissolved in benzene, and insoluble materials were removed by filtration. The obtained filtrate was freeze-dried to remove the solvent, thereby obtaining tetra-PEG-COOH as a white solid whose terminal was modified with a carboxyl group. Dissolve the tetra-PEG-COOH (0.2165mmol, 4.33g, 1.0equiv) in THF, add N-hydroxysuccinimide (2.589mmol, 0.299g, 12equiv), N,N'-diisopropylbutane Diimide (1.732 mmol, 0.269 mL, 8.0 equiv) was heated and stirred at 40°C for 3 hours. After the reaction, the solvent was distilled off under reduced pressure with an evaporator. Dissolve in chloroform, extract three times with saturated saline, and extract the chloroform layer. Furthermore, after dehydrating and filtering with magnesium sulfate, the solvent was distilled off under reduced pressure with an evaporator. The obtained residue was freeze-dried to obtain TNPEG as a white solid. The chemical formula of the prepared TNPEG is shown in formula (IIa). In formula (IIa), n ₂₁ to n ₂₄ are 45 to 55 when the molecular weight of TNPEG is about 10,000 (10k), and 90 to 115 when the molecular weight is about 20,000 (20k).

[Example 2]

Synthesis of gel precursor mass

The gel precursor group that becomes the precursor in the gelation reaction is synthesized in the following manner.

(1) Gel precursor group 1 [TAPEG+TNPEG]

First, TAPEG (1.0×10 ⁴ g/mol) and TNPEG (1.0×10 ⁴ g/mol) synthesized in Example 1 were dissolved in equal amounts of 81 mM phosphate buffer and citric acid-phosphate buffer, respectively. At this time, the material mass ratio was set to TAPEG/TNPEG=1/0.23, and the overall polymer concentration was set to 60g/L. The two parts of the obtained solution were mixed in another container, and defoamed and stirred by a rotation and revolution mixer. Thereafter, the mixed solution was quickly transferred to a centrifuge tube, and capped to prevent drying, and then allowed to stand at room temperature for 12 hours.

The time changes of the storage elastic modulus G'and the loss elastic modulus G" in this step are shown in Fig. 3. At the end of the reaction, there is a relationship of G'<G", which means that the gel-formed sol state is not reached Of polymer clusters.

(2) Gel precursor group 2 [SHPEG+MAPEG]

Using SHPEG and MAPEG, the gel precursor group 2 was synthesized in the same manner. The overall polymer concentration is set to 60 g/L. At this time, a plurality of samples containing two kinds of gel precursor groups excessively containing either one in such a manner that SHPEG:MAPEG became a molar ratio of (1-r):r were prepared.

[Example 3]

Synthesis of polymer gel

Using the gel precursor group synthesized in Example 2, a polymer gel was synthesized as follows.

(1) Polymer gel 1 [TAPEG+TNPEG]

The solution of the gel precursor mass 1 obtained in Example 2 was diluted with water to 25 g/L. Calculate the amount of unreacted amine groups in the solution, add the cross-linking agent (bis(sulfobutanediimidyl) glutarate (BS ₂ G)) in the same amount as it is, and perform by rotating the revolution mixer Defoam and stir. Thereafter, the mixed solution was quickly transferred to a centrifuge tube, and capped to prevent drying, and then allowed to stand at room temperature for 12 hours.

The time changes of the storage elastic modulus G'and the loss elastic modulus G" in this step are shown in Fig. 4. At the end of the reaction, there is a relationship of G'>G", which means cross-linking by the gel precursor group Instead, a polymer gel is formed.

In addition, the reaction time when gelation is changed by changing the concentration of the gel precursor mass is shown in FIG. 5. The vertical axis of FIG. 5 is the gelation time t _gel (seconds), and the horizontal axis is the polymer content c (g/L) in the polymer gel. △ in the figure is an example of the polymer gel of the present invention gelled by a gel precursor group, ○ is a comparison of direct gelation from a polymer unit by a previous method without using a gel precursor group example. As a result, it can be seen that when the gel precursor group is gelled, a polymer gel is obtained with a shorter reaction time. Especially when the polymer content is low at about 8g/L, the previous method requires a gelation time of more than 7 hours. In contrast, when the gel precursor of the present invention is used, the gel is within 1.5 hours Change. In addition, in the higher concentration region, when the gel precursor group is used, the gelation time is less than 30 minutes.

2) Polymer gel 2 [SHPEG+MAPEG]

The gel precursor mass 2 obtained in Example 2 was used to prepare a polymer gel in the same manner. Dilute the gel precursor mass of SHPEG excess (10g/L; r=0.37) and the gel precursor mass of MAPEG excess (10g/L; r=0.63) with citrate buffer containing sodium chloride to 6g/L, mixed in equal amounts. As in FIG. 5, the reaction time when gelation is changed by changing the concentration of the gel precursor mass is shown in FIG. 6. ○ in the figure is an example of the polymer gel of the present invention gelled by a gel precursor group, □ is a comparison of direct gelation from a polymer unit by a previous method without using a gel precursor group example. In particular, when the polymer content is at a low concentration of about 7 g/L, when the gel precursor of the present invention is used, gelation takes 3 minutes. It indicates that the gel precursor can be injected into the eye during vitreous surgery to gel in vivo.

[Example 4]

Physical properties of gel precursor mass

1. The size of the gel precursor mass

The results of measuring the size distribution of the gel precursor mass 1 synthesized in Example 2 are shown in FIG. 7. Rh on the horizontal axis is the particle diameter (nm) of the gel precursor group, and G (Γ ^-1 ) on the vertical axis is the distribution function of the characteristic relaxation time. As a result, it can be seen that the particle diameter of the gel precursor group is hundreds of nm, and the largest is around 100 nm. Regarding the gel precursor group 2 synthesized in Example 2, approximately the same results were also obtained.

2. Modulus of elasticity

For the gel precursor mass 1 in solution, dynamic viscoelasticity measurement was performed using a rheometer (Physica MCR501, manufactured by Anton Paar), and the storage elastic modulus G'and the loss elastic modulus G" were calculated. As a result, at 1 Hz The range of G" is 0.1<G"<100Pa, and G'<G"<100 G'. Thus, as shown in FIG. 3 described above, it was confirmed that the gel precursor group 1 obtained in Example 2 had a structure that did not reach the gelation threshold. Regarding the gel precursor group 2 synthesized in Example 2, approximately the same results were also obtained.

3. Fractal dimension

The results of measuring the dynamic viscosity characteristics at the critical point of gelation when the initial concentrations of various polymer units are used are shown in FIG. 8. The vertical axis of Fig. 8 is the storage elastic modulus G'(○ in the figure) and the loss elastic modulus G" (△ in the figure), and the horizontal axis is the frequency. (a) to (d) are the conditions of the initial concentration As shown in Figure 8, as the initial concentration becomes lower, the power law of G'and G" increases. Using this result, the fractal dimension of the gel precursor mass is calculated by dynamic calibration theory. The result is shown in Fig. 9. The vertical axis of Fig. 9 is the fragment dimension, and the horizontal axis is the initial concentration. It can be seen from the figure that as the concentration becomes lower, the fractal dimension D deviates downward from the theoretical predicted value (dashed line in the figure), forming a more sparse structure.

[Example 5]

Physical properties of polymer gel

Furthermore, the polymer concentration dependence of the elastic modulus of the polymer gel 1 obtained in Example 3 was measured. As a result, as shown in FIG. 10, in a low-concentration region where the storage elastic modulus G′ is less than 400 Pa in a low-concentration region of 20 g/L, the elastic modulus is proportional to the polymer content. It proves that by using the method of gelation from the precursor gel group, the elastic modulus of the gel can also be controlled in the low elastic modulus region.

Similarly, the polymer concentration dependence of the elastic modulus of the polymer gel 2 obtained in Example 3 was measured. The results are shown in Figure 11. ○ in the figure is an embodiment of the polymer gel of the present invention gelled by a gel precursor group, □ is used without a gel precursor group Comparative example in which the former method directly gelled from the polymer unit. In any case, it is suggested that the polymer gel of the present invention exhibits a higher elastic modulus and forms an effective three-dimensional network structure.

Furthermore, in a pseudo-closed space, the time change of swelling of the polymer gel 1 obtained in Example 3 was observed. Place the polymer gel in a glass container, add phosphate buffer solution and let stand overnight. As a result, as shown in FIG. 12, there was no volume change in the solution. It is a result of the possibility that the polymer gel is not swollen in a semi-closed space and can be used in a closed space or a semi-closed space in vivo.

Furthermore, for the polymer gel 2 obtained in Example 3, the results of measuring the time change of the swelling pressure are shown in FIG. 13. ○ in the figure is an example of the polymer gel of the present invention gelled by a gel precursor group (polymer concentration 10 g/L), □ is not used by the gel precursor group and is obtained by the previous method. Comparative example of direct gelation of polymer units (polymer concentration 140 g/L). As shown in FIG. 13, in the comparative example, the balance reached 12 kPa with time, but in the polymer gel of the present invention, it is always constant at about 0.19 kPa. This result indicates that the polymer gel of the present invention can be used stably for a long time even when it is applied to a living body for a long period of time.

[Example 6]

Versatility of gel precursor mass

In various systems, a low-concentration gel was produced in the same order as the four-branched system, thereby studying the versatility of the gel precursor group.

[Three-branched system]

Tri-APEG (triamine-polyethylene glycol) and Tri-NPEG (tri-N-hydroxy-butadiene imide-polyethylene glycol (NHS-PEG)) with the same molecular weight of 2.0×10 ⁵ respectively Dissolve in an equal amount of 45mM phosphate buffer and citric acid-phosphate buffer. At this time, the mass ratio was set to Tri-APEG/Tri-NPEG=1/0.49, and the overall polymer concentration was set to 40g/L. The obtained two parts of the solution were mixed in another container, and defoamed and stirred by a rotation and revolution mixer. Thereafter, the mixed solution was quickly transferred to a centrifuge tube, and capped to prevent drying, and then allowed to stand at room temperature for 12 hours. The obtained solution was diluted with water to 25 g/L. Calculate the amount of unreacted amine groups in the solution, add the cross-linking agent (bis(sulfobutanediimidyl) glutarate (BS ₂ G)) in the same amount as it is, and perform by rotating the revolution mixer Defoam and stir. Thereafter, the mixed solution was quickly transferred to a centrifuge tube, and capped to prevent drying, and then allowed to stand at room temperature for 12 hours. Finally, the gel was obtained in the same manner as the four-branched system.

[Four-Branch/Two-Branch System]

Tetra-APEG (triamine-polyethylene glycol) and Linear-NPEG (linear-N-hydroxy-succinimide-polyethylene glycol (NHS) with molecular weights of 2.0×10 ⁵ and 1.0×10 ⁵ respectively -PEG)) were dissolved in equal amounts of 42 mM phosphate buffer and citric acid-phosphate buffer, respectively. At this time, the mass ratio is set to Tri-APEG/Tri-NPEG=1/1.17, and the overall polymer concentration is set to 40g/L. The two parts of the obtained solution are mixed in another container, and defoamed and stirred by a rotation and revolution mixer. Thereafter, the mixed solution was quickly transferred to a centrifuge tube, and capped to prevent drying, and then allowed to stand at room temperature for 12 hours. The obtained solution was diluted with water to 25 g/L. Calculate the amount of unreacted amine groups in the solution, add the cross-linking agent (bis(sulfobutanediimide) glutarate (BS ₂ G)) in the same amount as it is, and rotate the mixer Defoam and stir. Thereafter, the mixed solution was quickly transferred to a centrifuge tube, and capped to prevent drying, and then allowed to stand at room temperature for 12 hours. Finally, the gel was obtained in the same manner as the four-branched system.

The three-branched system and the four-branched chain/two-branched system are also obtained in the same order as the four-branched system, so it can be seen that the versatility of the gel precursor group is high.

[Example 7]

Infusion experiment on mice

The polymer gel of the present invention is injected into mice in the following order.

1. Preparation of gel precursor mass

The mass ratio of tetra-PEG-maleimide (TMPEG) (1.0×10 ⁴ g/mol) and tetra-PEG-thiol (TTPEG) (1.0×10 ⁴ g/mol) becomes the following table It was measured in the same way and dissolved in equal amounts of citric acid-phosphate buffer (pH 5.8, 5mM (NaCl, 149mM)). At this time, the overall polymer concentration was set to 60 g/L. The two obtained solutions were mixed in a centrifuge tube, and capped to prevent drying, and then allowed to stand at room temperature for 12 hours.

2. Preparation of polymer gel

The gel precursor mass solution was measured in such a way that the total amount of polymer gel became 2 mL and the polymer concentration became 13 g/L (group 1) and 11 g/L (group 2), respectively, and injected into the syringe. In addition, regarding Group 1 and Group 2, the amounts of unreacted maleimide groups and thiol groups in the respective solutions were calculated, and the cross-linking agent (DL-dithiothreose) was measured separately in an equivalent amount Alcohol and 1,8-bismaleimide diethylene glycol). Dissolve the cross-linking agent in the total amount of polymer gel and the difference between the gel precursor group and the citric acid-phosphate buffer (pH value 5.8, 5mM (NaCl, 149mM)), and inject it into a syringe different from the above Another syringe. The two solutions were mixed using a three-way valve, and 1 mL was injected into the back of anesthetized mice. As a comparative example, TMPEG (monomer A) and TTPEG (monomer B) were dissolved in citric acid-phosphate buffer (pH 5.8, 5 mM (NaCl, 149 mM), respectively, so as to be 15 g/L. ), and samples of only citric acid-phosphate buffer (pH value 5.8, 5mM (NaCl, 149mM)) (control sample), were injected into the anesthetized mice 1mL. One week after the injection, the tissues of the mice were observed.

As a result, neither the group 1 nor the group 2 showed decomposition or rejection of the gel, and the presence of the gel was confirmed under the skin 1 week after the injection. On the other hand, when only the monomer is injected, it is decomposed without toxic effects. All mice were normal, with no change in body weight.

Claims (24)

A method for manufacturing a polymer gel, characterized in that it is a method for manufacturing a polymer gel in which gel precursor groups are cross-linked with each other to form a three-dimensional network structure, and includes: a) gelation that is not critical The step of crosslinking monomer units or polymer units at a concentration to form the gel precursor group, wherein the gel precursor group has G'<G" in storage elastic modulus G'and loss elastic modulus G" Relationship; and b) a step of obtaining a gel having a three-dimensional network structure by cross-linking the aforementioned gel precursor groups with a cross-linking agent. As in the manufacturing method of claim 1, the above-mentioned loss elastic modulus G" is in the range of 0.005 to 5 Pa at a frequency of 1 Hz. The manufacturing method according to claim 1 or 2, wherein the gel precursor mass has a fragmentary dimension of 1.5 to 2.5. The manufacturing method according to claim 1 or 2, wherein the aforementioned gel precursor group has a diameter in the range of 10 to 1000 nm. The manufacturing method according to claim 1 or 2, wherein the gel is a polymer content of 50 g/L or less. The manufacturing method according to claim 1 or 2, wherein the monomer unit has a vinyl skeleton, or the polymer unit has a polyethylene glycol skeleton or a polyethylene skeleton. The manufacturing method according to claim 1 or 2, wherein the gel precursor group includes a first polymer unit having at least one nucleophilic functional group at the side chain or terminal, and at least one at the side chain or terminal The second polymer unit of the electrophilic functional group. The manufacturing method according to claim 7, wherein the nucleophilic functional group is selected from the group consisting of an amine group, -SH, and -CO ₂ PhNO ₂ , and the electrophilic functional group is selected from N-hydroxy-butadiene A group consisting of an amine (NHS) group, a sulfobutanediimide group, a maleimide group, a phthalimide group, an imidazolyl group, an acryloyl group, and a nitrophenyl group. The manufacturing method according to claim 7, wherein the gel precursor group includes a first gel precursor group and a second gel precursor group, and the content of the first polymer unit of the first gel precursor group is higher than that of the first 2 The content of the polymer unit is large, and the content of the second polymer unit of the second gel precursor group is greater than the content of the first polymer unit. The manufacturing method according to claim 1 or 2, wherein the above step b) is performed with a reaction time within 1 hour. The manufacturing method according to claim 1 or 2, wherein the cross-linking agent in the above step b) is bis(sulfosuccinimide) glutarate (BS ₂ G) or DL-dithiothreitol ( DTT), or a synthetic peptide with a thiol group at the end. A gel precursor group obtained by cross-linking monomer units or polymer units that have not reached the critical gelation concentration, and containing a solvent, having storage elastic modulus G'and loss elastic modulus G" G'<G" is related and has a diameter in the range of 10~1000nm. As in the gel precursor mass of claim 12, the above-mentioned loss elastic modulus G" is in the range of 0.005 to 5 Pa at a frequency of 1 Hz. The gel precursor mass according to claim 12 or 13, wherein the gel precursor mass has a fragmentary dimension of 1.5~2.5. The gel precursor group according to claim 12 or 13, wherein the monomer unit has a vinyl skeleton, or the polymer unit has a polyethylene glycol skeleton or a polyethylene skeleton. The gel precursor group according to claim 12 or 13, which comprises a first polymer unit having more than one nucleophilic functional group on the side chain or terminal, and more than one electrophilic group on the side chain or terminal The second polymer unit of the functional group. The gel precursor group according to claim 16, wherein the nucleophilic functional group is selected from the group consisting of amine group, -SH, and -CO ₂ PhNO ₂ , and the electrophilic functional group is selected from N-hydroxy-butyl A group consisting of diimide (NHS) group, sulfobutanediimide group, maleimide group, phthalimide group, imidazolyl group, acryloyl group, and nitrophenyl group . A polymer gel obtained by the manufacturing method according to any one of claims 1 to 11. A polymer gel, characterized in that it is formed by a cross-linking of polymer units to form a three-dimensional network structure, and contains a solvent, has a polymer content of 50g/L or less, at a frequency of 1Hz is 1 ~ The storage elastic modulus G'of 10000Pa and the fractal dimension of 1.5~3.0, and the volume of the above polymer gel in the range of 30~40℃ in the aqueous solution is 90% relative to the volume when the gel is made The swelling degree in the range of ~500% volume change, and has a swelling pressure of 0.001~5kPa. The polymer gel of claim 19 has a loss elastic modulus G" of 1-100 Pa. The polymer gel according to claim 19 or 20, wherein the polymer unit has a polyethylene glycol skeleton or a polyethylene skeleton. The polymer gel according to claim 19 or 20, wherein the polymer unit includes a first polymer unit having one or more nucleophilic functional groups at the side chain or terminal, and one or more at the side chain or terminal The second polymer unit of the electrophilic functional group. The polymer gel according to claim 22, wherein the nucleophilic functional group is selected from the group consisting of amine group, -SH, and -CO ₂ PhNO ₂ , and the electrophilic functional group is selected from N-hydroxy-butane The group consisting of amide imine (NHS) group, sulfobutane imide group, maleimide group, phthalimide group, imidazolyl group, acryl group, and nitrophenyl group. The polymer gel according to claim 19, wherein the swelling degree is in the range of 100 to 200%, and the swelling pressure is 0.1 to 2 kPa.

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